scholarly journals Fibro-adipogenesis in Injured Rotator Cuff Muscle

Author(s):  
Ajith K. Subhash ◽  
Michael Davies ◽  
Andrew Gatto ◽  
Jacob M. Bogdanov ◽  
Rae Lan ◽  
...  

Abstract Purpose of Review Fibro-adipogenic progenitors were first characterized in 2010 and later found to contribute significantly to muscle regeneration and mediate degenerative changes in muscle following injury. These progenitors were also found to have an influence on the rotator cuff muscle’s response to chronic injury which is defined by fibrosis accompanied by massive fatty degeneration. The purpose of this review is to highlight progenitor cells, their contribution to fibro-adipogenesis in rotator cuff tissue, and the factors influencing fibro-adipogenesis in this tissue. Recent Findings Fibro-adipogenic progenitors are a key mediator of the fatty infiltration notably prevalent in rotator cuff injury. Relative to other muscle groups, the rotator cuff has relatively high rates of fibro-adipogenesis following massive chronic rotator cuff tears. This may be linked to the pre-injury density of fibro-adipogenic progenitors in muscle tissue affecting post-injury levels of fibro-adipogenesis. In addition, suprascapular nerve injury in rat models of rotator cuff tears has demonstrated worse, histologic, and biomechanical properties and lower healing rates of rotator cuff repairs. However, fatty infiltration in the rotator cuff following suprascapular nerve compression has been shown to be reversible following release of the nerve compression. Summary The fibro-adipogenic response to acute and chronic injury in rotator cuff tissue is determined by a complex array of factors including progenitor cell influence, transcriptional pathways, chronicity of the injury, anatomic location of injury, microenvironmental influences, and the severity of nerve involvement. Elucidating the complex interactions of these factors will provide potential targets for therapeutic intervention in vivo.

2019 ◽  
Vol 47 (13) ◽  
pp. 3247-3255 ◽  
Author(s):  
Chongyang Wang ◽  
Wei Song ◽  
Bi Chen ◽  
Xudong Liu ◽  
Yaohua He

Background: Fatty infiltration, inflammation, and apoptosis are common degenerative changes in patients with chronic rotator cuff tears that can lead to muscle atrophy and can even result in massive irreparable rotator cuff tears. Some data have demonstrated the proregenerative, anti-inflammatory, and anti-apoptotic properties of stem cell–derived exosomes in some orthopaedic disorders, but their effect on torn rotator cuff muscles has never been investigated. Purpose: To study the effect of exosomes isolated from human adipose-derived stem cells (ASCs-Exos) on muscle degeneration, regeneration, and biomechanical properties in a rat model of a massive rotator cuff tear (MRCT). Study Design: Controlled laboratory study. Methods: A bilateral supraspinatus and infraspinatus tenotomy was performed on rats to create an MRCT model. Forty-two rats were randomly assigned to 3 groups: the sham surgery group, the saline group (lesions treated with a saline injection), and the ASCs-Exos group (lesions treated with an ASCs-Exos injection). Wet muscle weight, fatty infiltration, inflammation, vascularization, regeneration, and biomechanical properties were evaluated at 8 and 16 weeks after surgery. Results: The results revealed that the ASCs-Exos treatment could prevent the atrophy, fatty infiltration, inflammation, and vascularization of muscles in the MRCT model ( P < .001). Additionally, the myofiber regeneration and biomechanical properties of ASCs-Exos-treated rotator cuffs were significantly elevated compared with those in the saline-treated group ( P < .001). Conclusion: This study demonstrates that ASCs-Exos can effectively decrease atrophy and degeneration and improve muscle regeneration and biomechanical properties in torn rotator cuff muscles. Clinical Relevance: ASCs-Exos can be used as a new cell-free approach to prevent the muscle degeneration associated with torn rotator cuffs and may be helpful to repair torn rotator cuffs. Nevertheless, further work needs to be done in a large animal model owing to the inherent regenerative potential possessed by rodents.


2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Marie Protais ◽  
Maxime Laurent-Perrot ◽  
Mickaël Artuso ◽  
M. Christian Moody ◽  
Alain Sautet ◽  
...  

Abstract Background Irreparable rotator cuff tears are common and difficult to treat. Techniques for “filling the loss of substance” require fixation to the rotator cuff stump (tendon augmentation) or to the glenoid (superior capsular reconstruction), which are complicated by the narrow working zone of the subacromial space. The main objective of this study was to determine whether a braided graft of gracilis (GR) and semitendinosus (ST) could fill a loss of tendon substance from an irreparable rupture of the supra- and infraspinatus, by fixing the graft to the greater tuberosity and the spine of the scapula. Methods This was a cadaveric study with the use of ten specimens. The GRA and ST tendons were harvested, braided and reinforced with suture. An experimental tear of the supraspinatus (SS) and upper infraspinatus (IS) retracted at the glenoid was made. The GRAST transplant was positioned over the tear. The transplant was attached to the greater tuberosity by two anchors and then attached to the medial third of the scapular spine by trans-osseous stitching. The percentage of filling obtained was then measured and passive mobility of the shoulder was assessed. We proceeded to the same technique under arthroscopy for a 73 years old patient whom we treated for a painful shoulder with irreparable cuff tear. We inserted a GRAST graft using arthroscopy. Results The Braided-GRAST allowed a 100% filling of the loss of tendon substance. Mobility was complete in all cases. Conclusion This technique simplifies the medial fixation and restores the musculo-tendinous chain where current grafting techniques only fill a tendinous defect. The transplant could have a subacromial “spacer” effect and lower the humeral head. The donor site morbidity and the fate of the transplant in-vivo are two limits to be discussed. This anatomical study paves the way for clinical experimentation.


2018 ◽  
Vol 46 (14) ◽  
pp. 3486-3494 ◽  
Author(s):  
Mengcun Chen ◽  
Snehal S. Shetye ◽  
Julianne Huegel ◽  
Corinne N. Riggin ◽  
Daniel J. Gittings ◽  
...  

Background: Lesions of the long head of the biceps tendon are often associated with massive rotator cuff tears (MRCTs), and biceps tenotomy is frequently performed for pain relief and functional reservation. However, the efficacy and safety of biceps tenotomy regarding the effects on the surrounding tissues in chronic MRCT are unclear. Hypothesis: Biceps tenotomy would result in improved mechanical and histological properties of the intact subscapularis tendon and improved in vivo shoulder function while not compromising glenoid cartilage properties. Study Design: Controlled laboratory study. Methods: Right supraspinatus and infraspinatus tendons were detached in 25 male Sprague-Dawley rats, followed by 4 weeks of cage activity to create a chronic MRCT condition. Animals were randomly divided into 2 groups and received either biceps tenotomy (n = 11) or sham surgery (n = 14) and were sacrificed 4 weeks thereafter. Forelimb gait and ground-reaction forces were recorded 1 day before the tendon detachment (baseline), 1 day before the surgical intervention (biceps tenotomy or sham), and 3, 7, 10, 14, 21, and 28 days after the intervention to assess in vivo shoulder joint function. The subscapularis tendon and glenoid cartilage were randomly allocated for mechanical testing or histologic assessment after the sacrifice. Results: Compared with sham surgery, biceps tenotomy partially restored the in vivo shoulder joint function, with several gait and ground-reaction force parameters returning closer to preinjury baseline values at 4 weeks. With biceps tenotomy, mechanical properties of the subscapularis tendons were improved, while mechanical properties and histological Mankin scores of the glenoid cartilage were not diminished when compared with the sham group. Conclusion: Biceps tenotomy in the presence of chronic MRCT partially preserves overall shoulder function and potentially restores subscapularis tendon health without causing detrimental effects to joint cartilage. This laboratory study adds to the growing literature regarding the protective effects of biceps tenotomy on the shoulder joint in a chronic MRCT model. Clinical Relevance: This study provides important basic science evidence supporting the use of biceps tenotomy in patients with massive rotator cuff tears.


Orthopedics ◽  
2017 ◽  
Vol 41 (1) ◽  
pp. e15-e21 ◽  
Author(s):  
Jong Pil Yoon ◽  
Jae Wook Jung ◽  
Chang Hwa Lee ◽  
Young Gun Kim ◽  
Seok Won Chung ◽  
...  

2020 ◽  
Vol 48 (9) ◽  
pp. 2151-2160
Author(s):  
Jakob E. Schanda ◽  
Claudia Keibl ◽  
Patrick Heimel ◽  
Xavier Monforte ◽  
Stefan Tangl ◽  
...  

Background: Bone mineral density at the humeral head is reduced in patients with chronic rotator cuff tears. Bone loss in the humeral head is associated with repair failure after rotator cuff reconstruction. Bisphosphonates (eg, zoledronic acid) increase bone mineral density. Hypothesis: Zoledronic acid improves bone mineral density of the humeral head and biomechanical properties of the enthesis after reconstruction of chronic rotator cuff tears in rats. Study Design: Controlled laboratory study. Methods: A total of 32 male Sprague-Dawley rats underwent unilateral (left) supraspinatus tenotomy with delayed transosseous rotator cuff reconstruction after 3 weeks. All rats were sacrificed 8 weeks after rotator cuff repair. Animals were randomly assigned to 1 of 2 groups. At 1 day after rotator cuff reconstruction, the intervention group was treated with a single subcutaneous dose of zoledronic acid at 100 µg/kg bodyweight, and the control group received 1 mL of subcutaneous saline solution. In 12 animals of each group, micro–computed tomography scans of both shoulders were performed as well as biomechanical testing of the supraspinatus enthesis of both sides. In 4 animals of each group, histological analyses were conducted. Results: In the intervention group, bone volume fraction (bone volume/total volume [BV/TV]) of the operated side was higher at the lateral humeral head ( P = .005) and the medial humeral head ( P = .010) compared with the control group. Trabecular number on the operated side was higher at the lateral humeral head ( P = .004) and the medial humeral head ( P = .001) in the intervention group. Maximum load to failure rates on the operated side were higher in the intervention group ( P < .001). Cortical thickness positively correlated with higher maximum load to failure rates in the intervention group ( r = 0.69; P = .026). Histological assessment revealed increased bone formation in the intervention group. Conclusion: Single-dose therapy of zoledronic acid provided an improvement of bone microarchitecture at the humeral head as well as an increase of maximum load to failure rates after transosseous reconstruction of chronic rotator cuff lesions in rats. Clinical Relevance: Zoledronic acid improves bone microarchitecture as well as biomechanical properties after reconstruction of chronic rotator cuff tears in rodents. These results need to be verified in clinical investigations.


2019 ◽  
Vol 160 (14) ◽  
pp. 533-539
Author(s):  
Imre Sallai ◽  
Márton Weidl ◽  
Attila Szatmári ◽  
Imre Antal ◽  
Gábor Skaliczki

Abstract: Introduction: In the case of rotator cuff tears, the severity of the muscle atrophy and fatty degeneration has an effect on the success of the repair and on the functional outcome after surgery. Aim: The ability of regeneration reduces with ageing; therefore, the study examined the atrophy and the fatty degeneration after rotator cuff repair in patients over 65. Method: Eleven patients over 65 years of age were involved whose surgery was performed at the Department of Orthopaedics of Semmelweis University between 2012 and 2015. Their average age was 71.9 years and the average follow-up period was 39.9 months. Tear sizes were C1 in 3 cases, C2 in 3 cases, C3 in 4 cases, and C4 in 1 case. Each patient had magnetic resonance examination before and after the repair; the muscle atrophy and fatty degeneration were evaluated together with the type of the tear. Visual analogue scale and Constant score were used for the assessment of the pain and the shoulder function. Results: The average Constant score was 75 points. The occupancy ratio – referring to the severity of the atrophy – did not show significant improvement. The change in fatty degeneration and the atrophy were examined in different groups according to the size of the tears. In each group, the results showed progression. Conclusions: After rotator cuff repair in patients over 65, fatty degeneration and muscle atrophy also show progression. No significant relationship was found between the size of the tear and fatty degeneration or between the size of the tear and muscle atrophy. Orv Hetil. 2019; 160(14): 533–539.


2019 ◽  
Vol 47 (3) ◽  
pp. 674-681 ◽  
Author(s):  
Jieun Kwon ◽  
Ye Hyun Lee ◽  
Sae Hoon Kim ◽  
Jung Hoon Ko ◽  
Byung Kyu Park ◽  
...  

Background: Limited information is available regarding the characteristics of delaminated rotator cuff tears as compared with nondelaminated tears. Furthermore, there is conflicting information regarding the effects of delamination on the anatomic healing of repaired cuffs. Purpose: To evaluate the characteristics and anatomic outcomes of delaminated rotator cuff tears in comparison with nondelaminated tears to determine whether delamination is a negative prognostic factor affecting rotator cuff repair outcomes. Study Design: Cohort study; Level of evidence, 3. Methods: Between 2010 and 2014, 1043 patients were enrolled in the study to assess the prevalence of delamination. Among them, the findings from 531 patients who underwent magnetic resonance imaging or computed tomographic arthrography at least 1 year after surgery were included to determine whether delamination was a negative prognostic factor affecting the anatomic outcomes of arthroscopic rotator cuff repair. Delamination was assessed intraoperatively and defined by distinguishable edge cleavage tearing or interstitial horizontal gap between the articular and bursal surfaces of the torn tendon. One of 3 repair techniques (modified Mason Allen, single row, or double row) was used according to tear configuration and tendon mobilization. The authors evaluated visual analog scale scores for pain and satisfaction and American Shoulder and Elbow Surgeons scores to quantify clinical outcomes. Results: The incidence of delamination was 42.9% (447 of 1043). As compared with those with nondelaminated tears, patients with delaminated tears were older ( P < .001) and had longer symptom duration ( P = .019), larger tear sizes and retractions ( P < .001 for both), higher grades of fatty infiltration of the rotator cuff muscles (all P < .001), and poorer tendon quality ( P < .001). The overall healing failure rate was 19.0% (101 of 531). In univariate analysis, the rate of healing failure for the repaired cuffs was significantly higher in the delaminated group (delaminated tears, 60 of 238, 25.2%; nondelaminated tears, 41 of 293, 14.0%; P = .001). However, results of subgroup and multivariate analyses showed that the presence of delamination was ultimately not an independent risk factor for the failure of cuff healing. Between the delaminated and nondelaminated groups, there was no significant difference in postoperative functional outcomes. Conclusion: The results suggest that delaminated rotator cuff tears might represent chronic degenerative tears of longer symptom duration, with larger tear sizes and higher grades of fatty infiltration in older patients. It appears that delamination could be a confounding factor, not an independent prognostic factor, affecting rotator cuff healing.


Author(s):  
Kirk C. McGilvray ◽  
Amy S. Lyons ◽  
A. Simon Turner ◽  
John D. MacGillivray ◽  
Struan H. Coleman ◽  
...  

Rotator cuff disorders are one of the most common soft tissue injuries of the musculoskeletal system [1], second only to lower back pain presentations in clinical frequency [2]. Surgical repairs of chronic, massive rotator cuff tears are associated with a high rate of complications, typically by full or partial re-rupture of the repair [3,4]. The literature is replete with clinical retrospective studies or evaluation of cadaveric shoulders [5], however these studies do not address the in vivo healing characteristics of a given surgical repair. The purpose of this study was to quantitatively describe the degree of shoulder healing via biomechanical analyses using an ovine chronic infraspinatus model that was repaired with and without a polyurethane scaffold rotator cuff repair (RCR) patch.


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